Follow-up after pulmonary valve replacement in adults with tetralogy of Fallot: association between QRS duration and outcome

The aim of this study was to analyze whether QRS duration, before and after pulmonary valve replacement (PVR), is related to long-term outcome in patients with tetralogy of Fallot (TOF).Key factors that determine outcome after PVR in adult TOF patients are largely unknown. Recognition of such factors assists the identification of patients at increased risk of adverse events.Adults who previously underwent total correction for TOF (n=90; age 31.4±10.3 years) and required PVR for pulmonary regurgitation were included. The QRS duration was measured pre-operatively and 6 months after PVR. The post-operative changes in QRS duration were calculated. Adverse events (death, re-PVR, ventricular tachycardia, and symptomatic heart failure) were noted during follow-up.During 5.5±3.5 years of follow-up, 13 adverse events occurred. The 5-year event-free survival rate was 76% for patients with a pre-operative QRS duration180 ms and 90% in patients with a QRS duration≤180 ms (p=0.037). For patients with a post-operative QRS duration180 ms, 5-year event-free survival was 71%, whereas it was 91% for patients with a post-operative QRS duration≤180 ms (p=0.004). After multivariate correction, a post-operative QRS duration180 ms (hazard ratio: 3.685, 95% confidence interval: 1.104 to 12.304, p0.05) and the absence of a reduction in QRS duration post-PVR (hazard ratio: 6.767, 95% confidence interval: 1.704 to 26.878, p0.01), was significantly associated with adverse outcome.Severe QRS prolongation, before or after PVR, and the absence of a reduction in QRS duration after PVR, are major determinants of adverse outcome during long-term follow-up of patients with TOF.